ABSTRACT
Pressurizedmetereddoseinhalers(pMDis)arethemostwidelyusedinhalationdeviceinthe treatmentofasthma[1].pMDisuseapropellanttoaerosolizeadrugformulation (micronizeddrugsuspendedinthepropellanttogetherwithasuitablesurfactant,e.g.oleic acid)intoacloudofrespirableparticles[2].Until1995,allpMDiscontained chlorofluorocarbon(CFC)propellants,whenthephase-outofCFCschallengedthe pharmaceuticalindustrytoreformulateanddesignreplacementproductswithalternative propellants-thehydrofluoralkanes(HFAs)[3].
